ABSTRACT
Clinical studies reveal that sarcopenia is a main cause of higher frailty, impairment, and loss of independence in elderly women than men. The difficulty in defining sarcopenia has created challenges in determining the best treatment for patients with the disease. Most of the intrinsic as well as extrinsic muscle changes that occur with age are believed to be involved in the development of sarcopenia. Loss of skeletal muscle in sarcopenia may result from reduction in muscle protein synthesis and/or increased muscle protein breakdown, both of which are associated with inflammation. Identification of the central role of testosterone in metabolism and its effects on mammalian target of rapamycin pathway have led it to become a subject of intense interest in aging research and pharmacological treatment for sarcopenia. Testosterone has direct effects on satellite cells, because they express the androgen receptor and in response to testosterone increase the satellite cell population.
